The Mount Sinai Hospital performs approximately 800 intestinal resections every year, constituting a potentially vast resource of tissues for basic investigation. For many years, the P.I. of the PPG (Dr. Mayer) has been working closely with Dr. Harpaz (Director of Gl Pathology) to secure surgical specimens for research, as evidenced by the Preliminary Results presented. Over the past granting period this facilitated the successful completion of human studies for this project demonstrating the success of more formally organizing a Pathology Core that simultaneously supports all projects in the current Program Project Grant. This resource is quite unique as it ensures integration across the several projects such that the same specimen is used for several different types of experiments to permit more meaningful interpretation of data. The Specific Aims of the Pathology Core are as follows: Specific Aim 1: To retrieve, process, and distribute suitable specimens for the four Projects as needed (human - projects 1-4;murine - projects 1-4). Specific Aim 2: To stabilize and preserve undistributed tissues for long-term storage and make them available to Projects or investigators as needed. Specific Aim 3: To maintain a detailed tissue database documenting the anatomic sources, the gross and microscopic pathological characteristics of the individual tissue specimens, and the clinical and pathological data pertaining to the patients from whom specimens were derived. Specific Aim 4: To perform blinded histologic evaluation and scoring of inflammation in the different murine models used in all projects. Immunohistochemistry, and RNA analysis is performed in the specific laboratories of the individual investigators according to their expertise (see below for specifics). Only specimen acquisition, cell isolation (accessioning tech), distribution, storage, histologic analysis and maintenance of the database is performed in this core. The budget reflects the costs of these latter functions.